When I first started taking Iodine (1 to 2 drops of Lugols a day) the back of my throat drained some sort of pus and bled for a couple days. It was very painful. I just held off on the Iodine for a few days, and it went away. Now I take between 18 and 20 drops a day with no problems. I never figured out what was going on either but at least now I know it happened to some one else.